Spark-plug indicator



C. F. PINNEO. SPARK PLUG INDICATOR. APPLICATION FILED JULY 3,1911.

1 ,306,231 Patented June 10, 1919.

2 SHEETS-SHEET I.

C. F. PINNEO. SPARK PLUG INDICATOR. APPLICATION FILED JULY 3,1917.

1,306,23 1 Patehted June 10, 1919.

2 SHEETSSHEET 2.

I E11 & Mgm m CHARLES FREMONT PINNEO, 0F DETROIT, MICHIGAN.

SPARK-PLUG INDICATOR.

Specification of Letters Patent.

Patented June 1'11, 1919.

Application filed July 3, 1917. Serial No. 178,462.

To all whom it may concern:

Be it known that I, CHARLES FREMONT .PINNno, a citizen of the United States, re-

siding at Detroit, in the county of Wayne and State of Michigan, have invented certain useful Improvements in Spark-Plug Indicators, of which the following is a specification, reference being had therein to the accompanying drawing.

The present. invention has reference generally to improvements in that class of inventions known as internal combustion engines, and more particularly relates to spark plug indicators.

As the primary aim and object of this invention consists in the provision of novel indicating means mounted on the dash board of a vehicle and operably connected to the spark plugs of the engine cylinders and also the magneto of the motor vehicle for showing the condition of the spark plugs when the engine is in operation, consequently enabling the chauffeur or driver to determine. the cause. of the 'engine trouble, whether the result of a foul plug, weak wiring connections, etc.

It is an additional and equally important object of this invention to provlde coiiperative switch means mounted on the casing and cooperating with the indicating means for removably arranging the indicating means in circuit with the spark plugs and magneto,

. thus permitting the chaufieur to test the en- Other improvements and novel details in the construction and arrangement of the va rious parts of the apparatus will be brought out more in detail in the descriptionto follow, which for a clear understanding ofthe invention should be considered in connection with the accompanying drawings forming a part hereof, and wherein is disclosed for the purpose of illustration a convenient and sat isfactory embodiment of the invention. It is to be noted in this connection that minor changes in the construction and arrangement of parts may be made without departing from the principle of operation of the va- I'lOllS parts.

The invention is clearly illustrated in the accompanying drawings in which Figure 1 1s adiagrammatic view showing the indicating tneans operably connected to the spark plug and to the magneto;

Fig. 2 is a front elevation of the indicating means partly in section;

Fig. 3 is a transverse section taken on line 3-3 of Fig. 2;

Fig. 4 is a side elevation showing one of the indicators applied to the spark plug and engine so that it may serve as an individual tester therefor;

Fig. 5 is an enlarged vertical section of one of the indicators;

Fig. 6 is a top plan view thereof;

Similar characters of reference are employed in all of the above described views, to indicate corresponding parts.

Referring now, more particularly, to the accompanying drawings there is provided an internal combustion engine of any suitable type the casing 1 of which supports cylinders 2 provided on the upper ends with spark plugs 3. A timer 4 is operably connected to the drive shaft 5 of the engine while conducting wires 7 lead from the timer and have their outer terminals secured to the spark plugs. 3. A magneto 8 is now employed and is operably connected to the timer by means of wires v9 which together with the wires 7 conduct current to the spark plugs 3. Another conducting wire 10 is connected as at 11 to the engine casing 1 so as to be grounded thereto while a switch 12 is interposed in the wire 8. A suitable source of energy such as a plurality of batteries 13 are electrically connected to the portions .of the wiring 10 on opposite sides of the switch 12 by means of conducting wires 14 while one of these wires is also provided with aswitch 15. By this arrangement it will be appreciated that the engine can be operated either on the magneto when the switch 12 is closed and the switch 15 open or else it can be operated on the batteries when the switch 12 is open and the switch 15 is closed. 1

With a view toward providing improved spark indicating means for enabling the driver to locate the englne trouble, a casing 16 is attached to a dash board 17 of a motor vehicle while supported in suitable openings in the front face of the-casing are a plurality of spark plug indicators each indicated in their entirety by the numeral 18, and each of which is operatively interposed in the corresponding conducting wires 7 in a manner that will hereinafter become apparent.

Each of the indicators in'this instance consists of acylindrical body-19 formed of insulating material and having the respective ends ex-teriorly threaded as at 20 and pro vided on the inner surface adjacent the outer end with anannular rib 21 for a purpose that will presently appear. Arranged in the body is a disk 22 formed of suitable insulating material such, as fiber. This disk is provided with opposed openings 23 for supporting conducting terminals 24 the outer ends of which are curved toward each other. as at 25,

and terminate in heads 26, the space between which serves as aspark jumping gap. The opposite ends of'these terminals are interposed in the conducting wire 7. A piece of transparentmaterial such as a magnifying glass 27 is inserted in the outer end of the body and rests against the annular rib 21 while flanged nuts 28 are indicated on the threaded portions 20 and are provided with inwardly extending angular flanges 29 which are respectively engageable with the outer surfaces of the glass 27 and the disk. 22 so as to effectively support both the disk and the glass in the body. The outer face of the casing 16 is also provided with numerals positioned beneath each of the openings and indicative of the various cylinders so that the driver may look through the several magnifying glasses 27 to determine the condition of the extending spark plugs.

As intimated, improved means have bee provided for bridging-the connections between the conductin wires 7 in order that current'may pass rig t through theconducting wires without actuating the indicating means. In reducing this feature of the invention to practice, a bar 30 is slidably mounted in the top' of the casing 16 while depending therefrom at spaced intervals are a plurality of conducting yokes 31, the terminals 32 of which are arranged so as to .be placed in removable contact with the. perticns of the conducting wires 7 on opposite sides of the indicators 18. vA handle 33 is formed on the bar and. is slidably mounted through .the top of ,the casing 16 so that thedriyer when'desiring-to test the spark plugs may slide the bar tothefright to disengage the yoke fromth'e wires 7 thus letting the current jump the gaps in the indicators.

' Of course, normally the contacts'32 are in a position so that the current will flow throu h the yokes instead of umping the gaps in t e indicators.

In Figs. M inclusive there is. shown a modified form of this invention. Instead of any one or another one of similar construction is employed and used as an individual ignition tester. In reducing this feature of the invention to practice a bracket arm 34 is rigidly connected 'to the under surface of the disk 22 by means of a fastening device 35. A foot 36 formed on the terminal of the arm is bifurcated and provides attaching fingers 37 for engagement about a boss 38 formed on the top of the engine cylinder.

. This bracket and foot are formed of conducting material and have one of the terminals 24 connected thereto so that when the fingers are arranged about the boss 38 and the current flowing in the customary manner, it will be grounded to the boss. A U-shaped conducting clip 39 is electrically connected to the other terminal 24: and is adapted to be engaged on the top of the spark plug 40. It is desirable that the gap between the terminals 24' be narrower than the gap between the spark plug to which the device is connected when it is used as an individual tester so as to assure of a spark crossing the gap of the indicator in order that it may be visible through the magnifying glass to the user. I

The mode of operatinnin the present invention may be reviewed as follows:

Assuming that the parts have been assembled in the manner described and as indicated in Fig. 1 the current will flow when the engine is running from the magneto through the conducting wires 9. From the. timer it will flow through the conducting wires. 7 by way of the .yokes 31- to the spark plug where it will jump the gap and then pass through the wire 10 and .back to themagneto. Itis-to be appreciated-that when the switch. 30 is in an open position current will flow into one of the terminals 24, jump the gap between the. heads 26 and then flow through the other termlnal to the spark plugs by way of the wire 7. When the engine is running on a battery, the switch 12 is-open while the switch 15 is closed, current of course passing through the recess of'the electrical supply circuit in the same manner.

As manypchanges could be made in the above construction and many apparently widely different embodiments of this invention could be made without departing from the scope thereof, and it'isinten'ded that all matter contained in the above description. or showntin theaccompanying drawings shall be interpreted as illustrative and not in a might be said to. fall therebetween.

Having thus fully described this invention, what is claimed as new and desired to be secured by Letters-Patent, is

In combination with the spark plugs in an internal combustion engine and the current su bply for the spark plug, of a rigidly mounted casing provided in one face with a series of openings, a plurality of indicators mounted in the openings, each of the indicators including a cylindrical body formed of insulating material, and having the respective ends threaded exteriorly, an annular rib formed onthe inner surface of the body of each indicator at the outer end, an insulating disk mounted in the inner end of each body, conducting terminals supported by the disk and arranged in closely spaced parallel relation with each other and providing a spark jumping gap, a magnifying glass mounted within the outer end of each body and supported by the rib through which the spark gaps are visible, nuts for engagement with the respective threaded extremities of the body, flanges carried by the nuts forsupporting the disks and for retaining the glass in position, the outer ends of the terminals being elect'riailly connected to the currentsupply, and switch means mounted within the casing for controlling the passage of curv rent through the indicators.

In testimony whereof I athx my signature.

CHARLES FREMONT PINNEO. 

